Roller transfer conveyor

ABSTRACT

A conveyor for moving articles such as pallets in a main path and selectively in a transfer path at right angles to the main path. The article is supported by a plurality of generally spherical elements mounted at desired intervals along each of a plurality of parallel shafts. Each spherical element consists of a pair of spherical segments forming portions of a sphere centered on a shaft and rotatable therewith, the segments being independently rotatable on an axis normal to the shaft. When the shafts are rotated by driving means, an article is moved by the elements in the main path. When the shafts are stopped with the axes of rotation of the spherical segments at about 45* to the base plane of an article, it is movable in the transfer path with independent rotation of the spherical segments which the article engages.

United States Patent Becker 1 July 25, 1972 [5 ROLLER TRANSFER CONVEYOROTHER PUBLICATIONS [72] Inventor: Raymond M. Becker, Oden, Mich.Kornylak Corp.. bulletin 2003 (Transweel) July 15, 1970 pp.

7 l- 8 [73] Assignee: Jervis B. Webb Company Primar Examiner-Richard E.Ae erter 22 Fl d: A ll 13 1971 g l 1 l 6 pr Assistant ExaminerD0uglas D.Watts [21 1 Appl. No.: 133,491 AttorneyFarley, Forster & Farley [57]ABSTRACT [52] U.S. Cl ..l98/l05, 193/35 MD [51] Int. Cl ..B65g 37/00 Aconveyor for movmg amcles Such as pallets m a mam path [58] Field ofSearch 193/35 MD 36 198/105 and selectively in a transfer path at rightangles to the main {98/21 2 path. The article is supported by aplurality of generally spherical elements mounted at desired intervalsalong each of a plurality of parallel shafts. Each spherical elementconsists of a [56] References cued pair of spherical segments formingportions of a sphere centered on a shaft and rotatable therewith, thesegments being UNITED STATES PATENTS independently rotatable on an axisnormal to the shaft. When 461,901 10/1891 Allis ..19s/105 x the shaftsare rotated by driving means, an article is moved y 3,552,541 1 1971Riggs ..193/37 x the elements in the main P when the shafts are PP l [2385 1 1/1 915 C 0 Op er 193 /3 5 MD with the axes of rotation of thespherical segments at about 45 to the base plane of an article, it ismovable in the transfer 2,789,708 4/1957 Payne ..l93/35 MDX p withindependent rotation of the Spherical segments which the articleengages.

14 Claims, 7 Drawing Figures o--o---o---o--0 o-v--o---o---o---o o---o-1@o--0 4 c --o---o---o--0 I 0 o-0--c -o /8 o -oo;o-0 o o o o o o o--o--ci-o--o [H] U BU U [1|] '9 11 n" 67 o o o 0 0 o o :o---o---o--o z/q G92its, 13 66w 0 o o o o o !O O- -0- o '-o I o o o o o o o o---o---o -o F T66 BB [1 1p nun Z0 4 L /6 .90

Patented July 25, 1972 3,679,043

5 Sheets-Sheet 1 FIG.l

/2 c --0- --0- --0- -0 I 0--0--0--c --0 //4 0-0 --9 U U U U U U '1 B 67unuuuum nn H I; p um] INVENTOR ATTORNEYS Patented July 25, 1972 3Sheets-Sheet 2 J@ml@@m@@@@ @jwm ATTORNEYS Patented July 25, 1972 5 Sheets-Sheet 5 lNVE N TOR RAYMOND A1. 54 6 K19? ATTORNEYS ROLLER TRANSFERCONVEYOR SUMMARY OF THE INVENTION This invention relates to improvementsin a conveyor of the type in which an article such as a pallet orcontainer is supported on a plurality of rotatable elements and ismovable in a main path and in a transfer path transversely to the mainpath.

In the handling of articles such as relatively heavy palletized loads orshipping containers, it is frequently desirable to shift the article atright angles to the path of a main conveyor onto a branch conveyor or astation to one side of the main conveyor. Prior conveyors capable ofimparting such a bi-directional movement to an article have in generaleither employed two sets of vertically shiftable article supportingelements, one set for each direction of movement, or a group of articlesupporting elements such as individual wheels which can be moved inunison about vertical pivots. Both of these prior types are relativelycomplicated structurally, particularly where the article supportingelements are power driven.

One of the principal objects of the present invention is to provide aconveyor on which articles can be moved in a main path and in a path atright angles thereto by the same article supporting elements, andwithout the necessity of changing the orientation of these elementsrelative to each other or to the main path of travel. Another object isto provide a conveyor having powered article supporting elements whichhave improved directional control over the movement of an article.

A conveyor constructed in accordance with the invention has a pluralityof spaced parallel shafts mounted on suitable frame structure, with"each shaft having a plurality of article supporting elements mountedthereon in spaced relation longitudinally of the shaft for rotationtherewith. Each article supporting element includes a pair of sphericalsegments independently rotatable on an axis normal to the axis of theshaft, the pair of segments forming portions of the sphere whose centeris coincident with the axis of the shaft. The shafts are rotatable inunison by suitable driving means so that the article supporting elementson the shafts are capable of moving an article engaged thereby in adirection normal to the axes of the shafts, which direction may beconsidered that of a main path of article travel. In order to move thearticle in a path at right angles to the main path, rotation of theshafts is stopped when the axes on which the spherical segments areindependently rotatable lie at angles of about 45 to the articlesupporting plane of the conveyor, enabling an article to be moved in adirection parallel to the axes of the shafts with independent rotationof the spherical segments engaged by the article.

Each pair of spherical segments is carried by a hub mounted on a shaft,the hub having a pair of oppositely projecting axles on which thespherical segments can independently rotate. In one form ofconstruction, the hub spaces the spherical segments to either side ofthe shaft, leaving a gap between them; and, in this construction,adjacent article supporting elements are arranged so that the axis ofrotation of the spherical segments of one article supporting element isin perpendicular relation to the axis of rotation of the next articlesupporting element. This arrangement is carried out from element toelement on the same shaft and on adjacent shafts so that when thedriving means is operated, an article is engageable by at least one-halfof the spherical segments at any one time. In another form ofconstruction, the pair of spherical segments and hub form asubstantially complete sphere at least with respect to the engagementthat takes place between an article and the supporting elements when theshafts are rotated.

In another form on conveyor construction, the shafts on which thearticle supporting elements are mounted are arranged in two groups, theaxes of the shafts of one group being in right angular relation to theaxes of the shafts in the other group. Rotation of the shafts of onegroup causes an article to be moved in one of two right angulardirections, this article movement being accompanied by independentrotation of spherical segments of the supporting elements of the othergroup.

Other features and advantages of the invention will appear from thefollowing description of the representative embodiments thereofdisclosed in the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view of a portionof a conveyor constructed in accordance with the invention;

FIG. 2 is an enlarged sectional elevation taken as indicated by the line2-2 of FIG. 3;

FIG. 3 is an enlarged plan view of the transfer portion of the conveyorof FIG. 1;

FIG. 4 is a schematic elevation illustrating movement of an article overthe portion of the conveyor indicated by the arrows 4-4 of FIG. 1;

FIG. 5 is an enlarged sectional elevation showing the construction ofone of the article supporting elements;

FIG. 6 is an enlarged sectional elevation similar to FIG. 5 showing analternate construction of one of the article supporting elements; and,

FIG. 7 is a schematic plan view of an alternate construction for thetransfer section of the conveyor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. I illustrates a conveyorof modular construction for the handling of articles such as palletizedloads or shipping containers in an air freight terminal. The conveyor isarranged to provide a reversible main path of travel indicated by thearrow 12 made up of a conveying module 14, a transfer module 16 and anysuccession of either or both of these modules that may be desired.Located to one side of the transfer module 16 is a storage module 18,and ordinarily a plurality of these storage modules will be arrangedalong the main path of travel to either or both sides thereof, eachstorage module or oppositely disposed pairs of storage modules beingadjacent to one of the transfer modules 16. Opposite the storage module18 illustrated is a turntable. module 20. This is a special module whichmay be required in cases where the palletized load or container is onlyaccessible from one end thereof for performing loading or unloadingoperations at one of the storage modules 18 of the conveyor, theturntable module enabling the articles to be properly oriented withrespect to the storage module to which it is to be delivered, bymanually rotating an article as indicated by the arrow 21.

An article supported on the transfer module 16 can be moved in either ofthe directions indicated by the arrow 12, and can also be moved ineither of the directions at right angles thereto as indicated by thearrow 17. The ability to move an article in the directions 12 or 17results from the construction of the invention, more fully described inFIGS. 2-5.

This construction includes a plurality of parallel shafts 24 extendingtransversely'to the directions 12, and a plurality of article supportingelements 26 mounted in spaced relation along each of the shafts 24. Theshafts are supported in suitable frame structure 28 and the elements 26define an article supporting plane. Preferably, the frame structure 28is relatively low in profile, as illustrated in FIG. 2, and designed sothat each of the modules of the conveyor can be mounted on a floor 30.

Each of the article supporting elements 26 (F IG. 5) consists of a pairof spherical segments 32 and 33 which are supported by mounting meansfor independent rotation on an axis normal to the axis of the shaft 24,the pair of segments 32 and 33 being spaced to either side of the shaftso as to form portions of a sphere, the center of which is coincidentwith the axis of the shaft. The mounting means comprises a hub 34mounted on a shaft 24 for rotation therewith and having a pair ofoppositely projecting axles 35 and 36 on which the segments 32 and 33are rotatably mounted and secured by suitable retaining rings 38.

As shown in FIG. 3, one of the shafts 24 is coupled to and is rotatableby a drive unit 40, and this rotation is transmitted to other shafts 24by chain and sprocket connections 42. When the drive unit 40 isactivated and the shafts are rotated, an article engaged by the elements26 on the shafts 24 will be advanced in the direction normal to the axesof the shafts 24, or in other words, in either of the directions 12.

In order to provide continuous support of an article, the elements 26are arranged so that the axes on which their spherical segments 32 and33 are independently rotatable lie in alternate 90 relationship. This isbest shown in FIGS. 3 and 4. Each of the shafts 24 defines a row of theelements 26 which are mounted thereon so that the axis of independentrotation of the spherical segments 32 and 33 of each element in the rowlies in a 90 relationship to each adjacent element in the row. Thisrelationship also applies with respect to adjacent rows. As a result,when the gap between the spherical segments 32 and 33 of one element 26is upper most, a spherical segment of four adjacent elements 26 is inposition to support an article. In most instances, the bottom of anarticle will have sufficient rigidity to be adequately supported by thisarrangement of elements 26. However, the alternate construction shown inFIG. 6 can be employed if desired. This construction employs a hub 44which includes a portion 45 in the shape of a spherical segment, theportion 45 together with the segments 32 and 33 constitutingsubstantially a complete spherical periphery in a directionperpendicular to the axis of the shaft 24.

Operation of the conveyor of FIG. 1 with respect to movement of anarticle in one of the directions 12 is illustrated in FIG. 4, whichassumes that an article 50 is being moved by rotation of the supportingelements 26 of the module 14 in the direction of the transfer module I6,and it is desired to stop the article on the transfer module 16 in aposition in which the article can be transferred to one of the modules18 or 20. As the article 50 passes over the first row 51 of supportingelements of the transfer module 16, which are not powered, the articlecontacts an actuator 52 which closes a normally open limit switch 54.This energizes the drive unit 40 of the transfer module, and the articleis advanced by rotation of the powered supporting elements 26 thereofand contacts an actuator 56 which opens a normally closed limit switch58. The limit switch 58 and a second normally closed limit switch 60 arearranged in parallel in the circuit to the motor of the drive unit 40.The limit switch 60 is actuated by one of the lobes 61 of a cam 62mounted on one ofthe shafts 24, the lobes 61 being arranged at 90intervals relative to the axis of the shaft 24 and in relation to theaxes ofindependent rotation of the spherical segments 32 and 33 suchthat when the limit switch 60 is actuated by one of the lobes 61 theseaxes lie at angles of approximately 45 to the article supporting planeof the conveyor.

When the limit switch 58 is actuated, the drive unit continues tooperate until the limit switch 60 is also actuated by one of the lobes61. This breaks the circuit to the drive unit 40 which is equipped witha suitable braking device such as a magnetic brake so that the unitstops and the axes of independent rotation of the spherical segments 32and 33 of all driven article supporting elements 26 lie in theaforementioned 45 relationship to the article supporting plane. With thesupporting elements 26 positioned in this manner, the article 50 can bemoved in either of the directions 17, and the transfer module '16 andadjacent modules 18 and 20 may be equipped with a suitable auxiliarypower device for moving the article in a direction parallel to the axesof the shafts 24, this movement of the article being accompanied byrotation of the spherical segments 32 or 33 which support the article.

In the construction illustrated in FIGS. 1-3, the auxiliary conveyingdevice consists of a pair of transfer chains 66 and 67 extending betweenthe transfer modules 16 and storage module 18, and a second pair oftransfer chains 68 and 69 extending between the transfer module 16 andturntable module 20. A drive motor 70 (FIG. 1) is arranged to drive thetransfer chains 67 and 68; a second motor 72 drives the transfer chains68 and 69. As illustrated in FIG. 2, each set of transfer chains isequipped with suitable pushers 74 and 75.

An alternate construction of a transfer module 16 is illustrated in FIG.7. The shafls on which the article supporting elements 26 are mountedare arranged in two groups. All of the shafts of one group are parallelto each other and perpendicular to all of the shafts 82 in the othergroup. In a sense, the shafts are arranged in quandrants about thecenter of the transfer unit, one quandrant being composed of the shafts80 of one group and the adjacent quandrant being composed of shafts 82of the other group; and, the shafts of each quandrant gradually increasein length from the center of the module outwardly toward the sidesthereof.

All of the shafts 80 are coupled to a drive unit 84, and all of theshafts 82 are coupled to a drive unit 86. Each of the drive units 84 and86 is controlled in the manner illustrated in FIG. 4, and these unitswould be preferably suitably interlocked so that only one can beoperated at any given time. Thus, when one of the drive units 82 and 84is stopped, the group of shafts coupled thereto would be positioned sothat the axes of independent rotation of the spherical segments 32 and33 of the supporting elements 26 carried by these shafts lie inapproximate 45 relationship to the article supporting plane. Actuationof the other drive unit enables an article to be advanced by rotation ofthe group of shafts and article supporting elements driven thereby, thisarticle movement being accompanied by independent rotation of thespherical segments 32 and 33 of the article supporting elements 26carried by the shafts of the other group. 7

Certain other features and modifications will be briefly mentioned. InFIG. 1, the module 14 forming part of the main path of article travel isshown as having an article supporting plane formed by a plurality of theelements 26, constructed as shown in either of FIGS. 5 or 6. Obviously,some other form of construction, such as a conventional live rollerconveyor, could be employed for this module. It is believed, however,that the construction illustrated will be preferable in many instancesbecause more uniform tracking between an article and the conveyorresults from the plurality of point contacts between the article and thesupporting elements 26.

In the case of the storage module 18, uniform tracking may not be asimportant because of the relatively smaller distance the article wouldordinarily travel, and the article supporting surface may advantageouslybe formed by a plurality of free rollers 90, as illustrated.Alternately, a live roller conveyor section could be used, therebyeliminating the necessity for the auxiliary transfer chains 67 and 68.

The turntable module 20 is equipped with a pressure pad 92 moveableupwardly into engagement with the bottom of an article to form a pivotabout which the article may be rotated. The article supporting plane ofthis module 20 may be formed by a combination of the article supportingelements 26 and conventional 45 free rollers 94, and the elements 26 onthis module may be powered or free, as desired. Alternately, this modulemay have an article supporting surface in the form of a conventionalball table.

A conveyor having an article supporting plane defined by the elements 26could obviously include curved sections in which case the shafts 24 onwhich the elements 26 are mounted would not be arranged in mutuallyparallel relation.

What is claimed is:

I. In a conveyor having frame structure and a plurality of articlesupporting elements mounted thereon so as to define an articlesupporting plane, the improvement comprising:

a plurality of spaced shafts mounted on the frame structure,

each shaft having a plurality of article supporting elements mountedthereon in spaced relation longitudinally of such shaft for rotationtherewith;

each article supporting element including a pair of spherical segments,and mounting means rotatably supporting the pair of spherical segmentson an axis normal to the axis of the shaft and with the pair of segmentsforming portions of a sphere whose center is coincident with the axis ofthe shaft; and,

drive means Operable to rotate at least some of the shafts in unisonwhereby the article supporting elements are capable of moving an articleengaged thereby in directions normal to the axes of the shafts and toarrest such rotation of the shafts when the axes of the sphericalsegments lie at angles of about 45 relative to the article supportingplane whereby an article may be moved in a direction parallel to theaxes of the shafts with rotation of the spherical segments engaged bythe article.

2. A conveyor according to claim 1 wherein the mounting means ofadjacent article supporting elements are arranged so that the axis ofrotation of the spherical segments of one article supporting element isin perpendicular relation to the axis of rotation of the sphericalsegments of an adjacent article supporting element.

3. A conveyor according to claim 1 wherein the article supportingelements are mounted on the shafts in substantially parallel rows, andwherein the axis of rotation of the spherical segments of one articlesupporting element lies in substantially perpendicular relation to theaxes of rotation of the spherical segments of adjacent articlesupporting elements in the same row and to the axes of rotation of thespherical segments of adjacent article supporting elements in anadjacent row.

4. A conveyor according to claim 1 wherein the axes of rotation of thespherical segments of the article supporting elements are arranged sothat an article is engageable by at least one-half of the sphericalsegments at any one time when the drive means is operated.

5. A conveyor according to claim 1 wherein the mounting means for thespherical segments of each article supporting element comprises a hubfixed to a shaft, and a pair of axles carried by the hub and extendingoppositely therefrom on a common axis normal to the axis of such shaft,the pair of spherical segments being rotatably supported on the pair ofaxles.

6. A conveyor according to claim 5 wherein said hub includes a portionin the shape of a spherical segment, which portion together with saidpair of spherical segments forms substantially a complete sphericalsurface circumferentially of the shaft.

7. A conveyor according to claim I wherein the drive means includes adrive unit, drive transmitting means coupling the drive unit to theshafts, and control means for stopping the drive unit and shafts whenthe axes of the spherical segments lie in said angular relation of about45 to the article supporting plane.

8. A conveyor according to claim 1 further including control meansresponsive to movement of an article by rotation of the shafts forstopping such rotation when such article arrives at a selected positionon the conveyor and the shafts turn to positions in which the axes ofthe spherical segments lie in said angular relation of abOut 45 to thearticle supporting plane.

9. A conveyor according to claim 1 further including pusher meansengageable with an article supported on the conveyor for moving sucharticle in the direction parallel to the axes of the shafts.

10. A conveyor according to claim 9 wherein the pusher means are capableof moving an article in either direction parallel to the axes of theshafts.

11. A conveyor according to claim 1 further including means forming astation to which an article can be transferred by movement in thedirection parallel to the axes of said shafts, and means for moving sucharticle in the direction parallel to the axes of the shafts fortransferring the article to and from said station.

12. A conveyor according to claim 11 wherein the means for moving sucharticle includes a pusher.

13. A conveyor according to claim 1 wherein the shafts are arranged intwo groups, all of the shafts in one group being parallel to each otherand perependicular to all of the shafts in the other group, and whereinthe drive means is operable to rotate at least some of the shafts of oneof the roups.

A conveyor according to claim 13 urther ll'lCiUdll'lg second drive meansfor rotating at least some of the shafts of the other group when thedrive means for the shafts of the first group is stopped with the axesof the spherical segments of the supporting elements carried therebypositioned in said angular relation of about 45 to the articlesupporting plane.

1. In a conveyor having frame structure and a plurality of articlesupporting elements mounted thereon so as to define an articlesupporting plane, the improvement comprising: a plurality of spacedshafts mounted on the frame structure, each shaft having a plurality ofarticle supporting elements mounted thereon in spaced relationlongitudinally of such shaft for rotation therewith; each articlesupporting element including a pair of spherical segments, and mountingmeans rotatably supporting the pair of spherical segments on an axisnormal to the axis of the shaft and with the pair of segments formingportions of a sphere whose center is coincident with the axis of theshaft; and, drive means operable to rotate at least some of the shaftsin unison whereby the article supporting elements are capable of movingan article engaged thereby in directions normal to the axes of theshafts and to arrest such rotation of the shafts when the axes of thespherical segments lie at angles of about 45* relative to the articlesupporting plane whereby an article may be moved in a direction parallelto the axes of the shafts with rotation of the spherical segmentsengaged by the article.
 2. A conveyor according to claim 1 wherein themounting means of adjacent article supporting elements are arranged sothat the axis of rotation of the spherical segments of one articlesupporting element is in perpendicular relation to the axis of rotationof the spherical segments of an adjacent article supporting element. 3.A conveyor according to claim 1 wherein the article supporting elementsare mounted on the shafts in substantially parallel rows, and whereinthe axis of rotation of the spherical segments of one article supportingelement lies in substantially perpendicular relation to the axes ofrotation of the spherical segments of adjacent article supportingelements in the same row and to the axes of rotation of the sphericalsegments of adjacent article supporting elements in an adjacent row. 4.A conveyor according to claim 1 wherein the axes of rotation of thespherical segments of the article supporting elements are arranged sothat an article is engageable by at least one-half of the sphericalsegments at any one time when the drive means is operated.
 5. A conveyoraccording to claim 1 wherein the mounting means for the sphericalsegments of each article supporting element comprises a hub fixed to ashaft, and a pair of axles carried by the hub and extending oppositelytherefrom on a common axis normal to the axis of such shaft, the pair ofspherical segments being rotatably supported on the pair of axles.
 6. Aconveyor according to claim 5 wherein said hub includes a portion in theshape of a spherical segment, which portion together with said pair ofspherical segments forms substantially a complete spherical surfacecircumferentially of the shaft.
 7. A conveyor according to claim 1wherein the drive means includes a drive unit, drive transmitting meanscoupling the drive unit to the shafts, and control means for stoppingthe drive unit and shafts when the axes of the spherical segments lie insaid angular relation of about 45* to the article supporting plane.
 8. Aconveyor according to claim 1 further including control means responsiveto movement of an article by rotation of the shafts for stopping suchrotation when such article arrives at a selected position on theconveyor and the shafts turn to positions in which the axes of thespherical segments lie in said angular relation of abOut 45* to thearticle supporting plane.
 9. A conveyor according to claim 1 furtherincluding pusher means engageable with an article supported on theconveyor for moving such article in the direction parallel to the axesof the shafts.
 10. A conveyor according to claim 9 wherein the pushermeans are capable of moving an article in either direction parallel tothe axes of the shafts.
 11. A conveyor according to claim 1 furtherincluding means forming a station to which an article can be transferredby movement in the direction parallel to the axes of said shafts, andmeans for moving such article in the direction parallel to the axes ofthe shafts for transferring the article to and from said station.
 12. Aconveyor according to claim 11 wherein the means for moving such articleincludes a pusher.
 13. A conveyor according to claim 1 wherein theshafts are arranged in two groups, all of the shafts in one group beingparallel to each other and perependicular to all of the shafts in theother group, and wherein the drive means is operable to rotate at leastsome of the shafts of one of the groups.
 14. A conveyor according toclaim 13 further including second drive means for rotating at least someof the shafts of the other group when the drive means for the shafts ofthe first group is stopped with the axes of the spherical segments ofthe supporting elements carried thereby positioned in said angularrelation of about 45* to the article supporting plane.